Summary: SGLT-2 inhibitors (or flozins) are the group of so-called „new diabetes drugs”. The mechanism of their action consists of the inhibition of the sodium-glucose co-transporter 2 located in the proximal tubule of the nephron which results in the inhibition of glucose reabsorption. This leads to an increased excretion of glucose in the urine and decrease in its concentration in the blood. Nowadays, SGLT-2 inhibitors are used not only in diabetology. They significantly reduce the risk of cardiovascular events, are used in chronic heart failure and slow down the progression of chronic kidney disease in both diabetic and non-diabetic patients. Despite numerous advantages, the use of flozins among patients with insulin deficiency may lead to an euglycemic ketoacidosis.